GB591247A - Improvements relating to metal-milling and other machine tools - Google Patents

Abstract

591,247. Actuating machines ; milling. CUNLIFFE & CROOM, Ltd., and WAINMAN, G. May 3, 1945, No. 11302. [Class 83 (iii)] A machine tool having a reciprocating toolhead or work-table such as a milling machine, has a high-speed approach and reverse as well as the normal cutting feed with separate controls for each speed, that for the high-speed being of the push-button switch type, and that for the normal speed being operated mechanically in such manner that when the highspeed control is neutralized it is held inoperative by the normal-speed control, with means for releasing the normal-speed drive at the end of each stroke. As applied to a milling machine, the normal feed of the table is engaged by turning handle 15, Fig. 2, to slide control-bar 13 and engage either of bevel-drives 5 and 6 on the feed-screw 4, and on applying the highspeed feed through push-button switch 16, the normal feed is over-run until checked by pawl 21 on the table depressing plunger 20. Bellcrank lever 19 is thereby moved and slides bar 18 to intercept the control at 16, in which position it is held by spring-loaded plunger 24, Fig. 5. This plunger is telescoped in sleeve 23 which is also spring-loaded to engage a notch in the control-bar 13 and which is displaced axially on turning handle 15; the plunger and sleeve are connected with lost motion by pin 29. Stops on the table return the control-bar 13 to neutral position and disengage the beveldrive, whereupon sleeve 23 re-enters the notch in the bar and moves plunger 24 from engagement with plunger 20 which, under spring pressure, moves upwards and withdraws the interference bar 18 from the push-button switch. The handle 15 is then moved in the reverse direction and push-button control 16 held in until the completion of the return stroke.